Layered Zeolite for Assembly of Two-Dimensional Separation Membranes for Hydrogen Purification

Membrane separation is an energy-efficient and environmentally friendly process. Two-dimensional (2D) molecular sieving membranes featuring unique nanopores and low transport resistance have the potential to achieve highly permeable and selective mixture separation with low energy consumption. High-aspect-ratio zeolite nanosheets with intrinsic molecular-sieving pores perpendicular to the layers are desirable building blocks for fabricating high-performance 2D zeolite membrane. However, a wider application of 2D zeolitic membranes is restricted by the limited number of recognized zeolite nanosheets. Herein, we report a swollen layered zeolite, ECNU-28, with SZR topology and eight-member ring (8-MR, 3.0 angstrom x4.8 angstrom) pores normal to the nanosheets. It can be easily exfoliated to construct 2D membrane, which shows a high hydrogen selectivity up to 130 from natural gas and is promising for hydrogen purification and greenhouse gas capture.

Automated summary

Membrane separation is an energy-efficient and environmentally friendly process that can achieve highly permeable and selective mixture separation. Two-dimensional molecular sieving membranes with unique nanopores and low transport resistance are desirable, but limited by the availability of recognized zeolite nanosheets. A newly reported swollen layered zeolite, ECNU-28, with high hydrogen selectivity offers promise for hydrogen purification and greenhouse gas capture.